The goal of the proposed project is to develop an analytical tool for large-scale detection of single-nucleotide polymorphisms (SNPs) in unlabeled, unamplified genomic or pooled nucleic acid samples. A dual hybridization utilizing a labeled, peptide nucleic acid (PNA, a nucleic acid analog) probe and an immobilized DNA probe will be performed. This innovative approach utilizes a long DNA probe to uniquely select the region of DNA near a specific gene and a short PNA probe that allows SNP identification. This simple method for SNP detection could be used in medical clinics for identifying disease causing mutations, such as human coagulation factor V Leiden, and in laboratories to study allele frequency and construct genetic maps. PROPOSED COMMERCIAL APPLICATIONS: This simple method for SNP detection would gain widespread acceptance in clinics for identifying genetic diseases and in laboratories to study allele frequency and construct genetic maps. Atom Sciences plans to market inexpensive kits that would use this technology.